This is a revision of a previous application that was not funded. It proposes longitudinal studies of the major consequences of Alzheimer's disease with the central goal of identifying the risk factors and time points in the disease course that are most susceptible to intervention against premature entry into nursing homes. Data collection for a cohort of 410 persons with Alzheimer's disease in the initial funding period was highly successful with excellent participation. The results suggested that behavior patterns of affected persons and caregiver factors predict nursing home entry equally well or more strongly than the major features of disease progression, cognitive impairment and physical disability. The proposed work will conduct longitudinal studies in two complementary cohorts of persons with Alzheimer's disease. It will use closely spaced sequential measures in an intensive observation cohort of 400 persons from a dementia evaluation center to (a) identify specific risk factors most predictive of nursing home entry within the broad areas of behavioral patterns and caregiver factors, (b) examine the relationships between caregiver and behavioral factors, testing the hypothesis that caregiver availability and three caregiver negative emotions, depression, anxiety and hostility, will be the central predictors of nursing home entry, with the effects of other behavioral and caregiver factors largely mediated through these central factors, and (c) identify the relation of these risk factors to the time course of disease progression and to the institutionalization event. In addition, the general population relevance of the findings will be examined by testing the central hypotheses in a cohort of 420 persons with Alzheimer's disease randomly sampled from a geographically defined biracial community.